Linear bi-component filament, fiber, or tape, and method of using thereof

ABSTRACT

The invention provides a linear or substantially linear bi-component filament, fiber, or tape including a first elastomeric component having a cross-sectional area of at least greater or lower than approximately 50 percent of the filament, fiber, or tape, and having a glass transition temperature of approximately −125 degrees to −10 degrees Celsius; and a second shape-memory polymeric component having a cross-sectional area of at least lower or greater than approximately 50 percent and being selected from one or more of a thermoplastic polyester-based or polyether based shape memory polyurethane. The second shape-memory polymeric component is positioned within the bi-component filament, fiber, or tape, such that a region of the second shape-memory polymeric component is asymmetrically disposed with respect to a central core of the bi-component filament, fiber, or tape. The second shape-memory polymeric component has a selectively engineered shape recovery temperature T r  between approximately 25° C. and 90° C.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priorities from U.S. provisional patentapplication Ser. No. 62/762,815 filed May 22, 2018 and U.S. provisionalpatent application Ser. No. 62/702,337 filed Jul. 23, 2018, and thedisclosures of which are incorporated herein by reference in theirentirety.

FIELD OF THE INVENTION

The present invention relates to a substantially linear bi-componentfilament, fiber, or tape, and method of using thereof.

BACKGROUND

Shape memory polymers are materials that have a first, “permanent”configuration and a second “temporary” configuration that results fromdeformation of the material. Upon receiving an external stimulus, suchas heat, solvent, electrical current, light, magnetic field, or changeof pH a thermal stimulus, the material returns to its “permanentconfiguration”. That is, the material “remembers” its original shape andreturns to that shape after undergoing the external stimulus.

So far, the most well-studied SMP is the thermally-triggered SMP whichtypically includes two phases: i) hard phase that determines thepermanent configuration and ii) soft phase that permits the formation ofthe temporary shape. The shape changing mechanism between the hard andsoft phase requires an elastic network which can recover the material tothe previous strain state while applying the stimulus, and switchingelements that can reversibly change from inelastic to mobile at atransition temperature, that is glass transition temperature (T_(g)) ormelting temperature (T_(m)). For a typical SMP production, it usuallychemically combines the elastic network and switching structuralelements to polymers or macromolecules. However, there are somedisadvantages such as those chemically cross-linked SMPs areunrecyclable, aging over time, or complicated chemical processes forlarge scale production.

Bi-component filament and fiber has been developed as a synthetic fibersince 1960s. Through such technology, two different polymers withsuitable viscosity, composition are co-extruded together into onefilament through a spinneret from two separate extenders. The filament'scross-section can be in different pattern including concentricsheath/core, eccentric sheath/core, side-by-side, pie wedge, islands/seamode, which depends on application requirement. For example, Chinesepatent application under the publication number CN104342802A disclosed adouble-component composite elastic fiber. The fiber disclosed thereinwas an extended filament which is formed by parallel composite spinningof polybutylene terephthalate and polyethylene glycol terephthalateaccording to a weight ratio of (70:30)-(30:0), crimp number of the fiberis 55-75/25 mm, and the crimp radius is below 1.0 mm. After thermaltreatment, the elastic elongation ratio of the fiber was 80%-120%, andthe elastic recovery ratio of the fiber was above 92%. Another Chinesepatent application under the publication number CN101126180A disclosed aside-by-side bi-component elastic fiber and its preparation method. Inthat Chinese application, by using the shrinkage PET, PBT or PTT, anytwo juxtaposed composite polymers could generate spring like crimpingformation with better elasticity after extending heating treatment, byvirtue of the difference in shrinkage properties. PCT application underthe publication number WO 2009099548 A2 described a method for producingself-crimping fluoropolymer(s) and perfluoropolymer(s) filamentscomprising; heating said fluoropolymer(s) and/or saidperfluoropolymer(s) to a molten state, extruding said fluoropolymer(s)and/or said perfluoropolymer(s) under pressure through spinneretplate(s) orifice(s) which create a filament, as a molten polymer thatexhibits differential die swell, wherein said filament, as a moltenpolymer expands sectionally and continuously along a longitudinal lengthof the resultant filament, and wherein said spinneret plate orifice(s)comprise a round hole shape with an ellipsoid peninsula creating anellipsoid cove gap in one section of said filament, as a molten polymerand differential die swell on opposing sides of said ellipsoid cove gapclose the gap creating a seam between said opposing sides such thatdifferential die swell around said ellipsoid cove gap creates unevenstresses along one portion of resulting filament thereby causing saidfilament to crimp, bend, deform and/or twist toward said seam in apreferred manner. United States Patent under the U.S. Pat. No. 4,424,257disclosed that a self-crimping multi-component polyamide filament isprovided and a process for producing the filament. In its simplest form,the filament was composed of two components each of which comprises apolyamide of the same chemical composition and one of which contains aminor amount of a polyolefin admixed with the polyamide. The filamentwas formed by co-extruding the components to form a conjugate filamentthat is attenuated in the molten state, solidified and then collected.Attenuation of the filament in the molten state imparted self-crimpingproperties and molecular orientation to the filament.

In view of the disadvantages of the existing SMP, there is a need for afiber, filament, or tape that has a stable, controllable, and tunablecrimping shape at different conditions.

SUMMARY OF THE INVENTION

Accordingly, a first aspect of the present invention provides a linearor substantially linear bi-component filament, fiber, or tape. Thefilament, fiber, or tape includes a first elastomeric component having across-sectional area of at least greater than approximately 50 percentof the filament, fiber, or tape, and having a glass transitiontemperature of approximately −125 degrees to −10 degrees Celsius; and asecond shape-memory polymeric component having a cross-sectional area ofat least lower than approximately 50 percent and being selected from oneor more of a thermoplastic polyester-based or polyether-based shapememory polyurethane, where the polyester-based polyurethane SMP includesa polycaprolactone-based polymer. The second shape-memory polymericcomponent is positioned within the bi-component filament, fiber, ortape, such that a region of the second shape-memory polymeric componentis asymmetrically disposed with respect to a central core of thebi-component filament, fiber, or tape. The second shape-memory polymericcomponent has a selectively engineered shape recovery temperature T_(r)between approximately 25° C. and 90° C., and the first elastomericcomponent is more elastic than that of the second shape-memory polymericcomponent at or lower than the selectively engineered shape memoryrecovery temperature.

A second aspect of the present invention is to provide a linear orsubstantially linear bi-component filament, fiber, or tape. Thefilament, fiber, or tape includes a first elastomeric component having across-sectional area of at least lower than approximately 50 percent ofthe filament, fiber, or tape, and having a glass transition temperatureof approximately −125 degrees to −10 degrees Celsius; a secondshape-memory polymeric component having a cross-sectional area of atleast greater than approximately 50 percent and being selected from oneor more of a thermoplastic polyester-based or polyether-base shapememory polyurethane, where the polyester-based polyurethane SMP includesa polycaprolactone-based polymer. The second shape-memory polymericcomponent is positioned within the bi-component filament, fiber, ortape, such that a region of the second shape-memory polymeric componentis asymmetrically disposed with respect to a central core of thebi-component filament, fiber, or tape. The second shape-memory polymericcomponent has a selectively engineered shape recovery temperature T_(r)between approximately 25° C. and 90° C., and the first elastomericcomponent is more elastic than that of the second shape-memory polymericcomponent at or lower than the selectively engineered shape memoryrecovery temperature.

In one embodiment, the bi-component filament, fiber, or tape isconfigured to assume a substantially helical configuration uponelongation of approximately 50% to approximately 300%, with the coilnumber per centimeter increasing with the increase of the elongationpercentage or the time period of elongation.

In another embodiment, the bi-component filament, fiber, or tape resumesa substantially linear shape upon heating to the selectively engineeredshape recovery temperature T_(r).

Alternatively, for the first and second aspects of the presentinvention, the proportion of the first elastomeric component and thesecond shape-memory polymeric component in the present bi-componentfilament, fiber, or tape can be defined by their respective weightratio. That is, the first elastomeric component is in a range of 10 to90 wt. % of the total weight of the bi-component filament, fiber, ortape while the second shape-memory polymeric component is in a range of90 to 10 wt. % of the total weight of the bi-component filament, fiber,or tape, wherein the weight ratio between the first elastomericcomponent and the second shape-memory polymeric component is 1-9:9-1 solong as the positioning of the first elastomeric component and thesecond shape-memory polymeric component with respect to thecross-sections along the bi-component filament, fiber, or tape remainsasymmetrical.

A third aspect of the present invention is to provide a method offabricating the present linear or substantially linear bi-componentfilament, fiber, or tape comprising any polymeric fiber formingtechniques such as wet, dry, gel, electro-, drawing spinning, either bysingle or multiple extrusion. Detail of the fabrication method isdescribed herein after by embodiments or examples.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention are described in more detailhereinafter with reference to the drawings, in which:

FIGS. 1A to 1C illustrate different embodiments of the present inventionin terms of different arrangement of the elastomer and the shape-memorypolymer (SMP) from the cross-sectional view in order to result indifferent three-dimensional structure of the present invention:

FIG. 1A illustrates an asymmetrical side-by-side arrangement of theelastomer and SMP according to an embodiment of the present invention;FIG. 1B illustrates an asymmetrical eccentric arrangement of theelastomer and SMP according to an embodiment of the present invention;FIG. 1C illustrates an asymmetrical and nearly rectangular arrangementof elastomer and SMP according to an embodiment of the presentinvention;

FIGS. 2A to 2D illustrate from cross-sectional view the structure of thebi-component filament or fiber according to various embodiments of thepresent invention: FIG. 2A illustrates a cross-section of thebi-component filament or fiber with an elastomer to SMP ratio of about2:1; FIG. 2B illustrates a cross-section of the bi-component filament orfiber with an elastomer to SMP ratio of about 3:1; FIG. 2C illustrates across-section of the bi-component filament or fiber with an elastomer toSMP ratio of about 3:2; FIG. 2D illustrates a cross-section of thebi-component filament or fiber with an elastomer to SMP ratio of about2:1; FIG. 2E illustrates a cross-section of the bi-component filament orfiber with an elastomer to shape memory polymer (SMP) ratio of about3:1;

FIG. 3 are images showing procedures of “stretching” and “releasing” thebi-component filament, fiber, or tape according to an embodiment of thepresent invention;

FIG. 4A illustrates that the coil diameter of examples 2 to 4 decreaseswith the increase of the elongation percentage, and the coil number percm increases approximately with the increase of the elongationpercentage;

FIG. 4B illustrates that the coil diameter of examples 5 to 7 decreaseswith the increase of the elongation percentage, and the coil number percm increases with the increase of the elongation percentage;

FIG. 5A is an image showing an example of the bi-component filament withestimated measurements of coil diameter and pitch distance;

FIG. 5B is an image showing another example of the bi-component filamentwith estimated measurements of filament diameter, coil diameter, andpitch distance.

DEFINITIONS

The term “linear” used herein to describe a state of the presentbi-component filament, fiber, or tape refers to a closely orsubstantially linear state of an as-formed bi-component filament, fiberor tape of the present invention which can be observed visually ordetermined qualitatively and/or quantitatively. In other words, thephrase “linear or substantially linear bi-component filament, fiber, ortape” or alike used herein could refer to an as-formed bi-componentfilament, fiber, or tape which is either or both qualitatively andquantitatively determined that it is arranged in or extending along astraight or nearly straight line.

The terms “filament” and “fiber” used herein, and sometimes they areused herein interchangeably, refer to a three-dimensional structure withan elongated morphology. In some contexts, the term “filament” or“fiber” can also refer to a slender threadlike object or article.

The term “elastomer” or “elastomeric component” used herein, orsometimes they are used interchangeably, refers to a material whichexhibits the property of elasticity, low Young's modulus (i.e. the ratioof tensile stress to tensile strain) and with the ability to deform whena stress is applied and resume to its original form (i.e., length,volume, shape, etc.) when the stress is removed. Examples of elastomersused in the present invention include, but are not limited to polyesteror polyether-based polyurethanes.

The term “shape memory polymer” or “shape-memory polymeric component”used herein, or sometimes they are used interchangeably, refers to aunique class of polymers or materials which exhibit the ability to fix atemporary shape and then resume to a prior state by an external stimulus(e.g. heat, radiation, solvent, electrical current, light, magneticfields, or a change in pH). Examples of shape memory polymers used inthe present invention include, but are not limited to polyester-based orpolyether-based shape memory polyurethane, where polyester-based SMPincludes but not limited to polycaprolactone-based SMP.

DETAILED DESCRIPTION

The present invention is not to be limited in scope by any of thefollowing descriptions. The following examples or embodiments arepresented for exemplification only.

Turning now to the drawings in detail, FIGS. 1A to 1C schematicallydepicts examples of configurations for linear bi-component filaments,fibers, or tapes of the present invention. The linear bi-componentfilaments, fibers, or tapes include elastomeric and shape memory polymerportions such that the filaments undergo deformation-based(stretching-induced) crimping, assuming a substantially helicalconfiguration following elongation on the order of approximately 50percent to approximately 300 percent. Upon heating to a temperaturegreater than a recover temperature, the materials resume the permanent,approximately linear configuration.

FIG. 1A and FIG. 1B show a cross-section of filament or fibers 100 whileFIG. 1C shows a cross-section of a tape 200. In each of thesearrangements, the shape memory polymeric region is indicated byreference numeral 10 and the elastomeric component is indicated byreference numeral 20.

As seen in FIGS. 1A-1C, a variety of configurations can be used in thebi-component filaments of the present invention. For example, in FIG.1A, the shape memory polymer 10 is formed in a region offset from thecore of the fiber or filament; similarly, in FIG. 1B, the shape memorypolymer 10 is also offset from a central core region of the tape. Thatis, the shape memory polymer region 10 is alwaysasymmetrically-positioned with respect to a center of thecross-sectional area of a filament, fiber, or tape. In these examples, abi-component filament can be made of thermoplastic polyurethaneelastomer (TPU) and SMP with a weight ratio from 90%:10% to 10%:90%. Thecross-section can be either side-by-side (FIG. 1A) or eccentricsheath/core (FIG. 1B). For the present bi-component tape (e.g., FIG.1C), it can also be made of thermoplastic polyurethane elastomer (TPU)and SMP with a weight ratio from 90%:10% to 10%:90%.

FIGS. 2A to 2E show some examples of asymmetrically arranging orpositioning the elastomer and SMP from the cross-sectional view to formthe bi-component filament or fiber. In those examples, each of theelastomer fiber(s) and SMP fiber(s) are longitudinally aligned with eachother according to an unequal number of fibers between two differentpolymeric fibers, e.g., 2:1, 3:1, 4:1, 1:2, 1:3, 1:4, etc. In otherwords, the ratio of the elastomer fiber to shape memory polymer fiber isx:y or y:x, where x is smaller or larger than y by at least 1 in thoseexamples. It should be understood that in terms of weight ratio, theratio between elastomer fibers and shape memory polymer fibers does nothave to be integers. The prerequisite to form the present bi-componentfilament, fiber, or tape is to position or arrange the elastomer and SMPasymmetrically with respect to the cross-sections along the bi-componentfilament, fiber, or tape such that the present bi-component filament,fiber, or tape is in linear or substantially linear state or shape whenthere is no corresponding external stimulus while it curls and formscorresponding number of coils upon stretching or elongation from about50% up to about 300% of its original length and for a period of time,and it is capable of resuming its linear or substantially linear stateor shape upon heating up to about its shape recovery temperature ofabout 25 to 90° C.

The present invention related to the manufacture and process for theproduction of filaments, fibers, tapes with “stretching induced crimpingand heat-induced uncurling” function, which are made from co-extrudedSMP and elastomer. Such smart function is arising from the bi-componentfilament structure, in which elastomer part keeps good elasticity atvarious temperature from room temperature to 90 degree Celsius, and SMPprovides pseudo-plasticity at temperature lower than T_(r), andelasticity at temperature above T_(r). Therefore, after stretching andreleasing at room temperature (lower than T_(r)), pseudo-plasticity inSMP side has trended to keep elongation, and at the same time,elasticity in elastomer side shrinks more or less. Therefore,self-crimping is made. Subsequently, if the crimped filament, fiber ortape is heated up to above T_(r), pseudo-plasticity of SMP will beremoved and turn to be elastic, which push the crimping shape beingstraightened instantly.

As shown in FIG. 3, through stretching to a certain value, such as 50%to 300%, at room temperature and releasing it to free standing status(301), the present bi-component filament instantly forms crimping shapefrom the substantially linear shape. Subsequently, for the crimpingshape, the uncurling process is easily realized through heating thefilament above shape recovery temperature of SMP (302). In the presentinvention, the shape recovery temperature of SMP used is above roomtemperature, such as from 25 to 90 degree Celsius.

To carry out bi-component filament extrusion, the spinneret withside-by-side or eccentric sheath/core two component structure is used.TPU with excellent elasticity would be a suitable candidate such asElastollan® C80A10, C85A10, Estane® S385A. SMP can include T_(g) (glasstransition as trigger temperature) type such as Diaplex 2520, 3520, 4520or T_(m) (melting point as trigger temperature) type such aspolycaprolactone based SMP as reported in a literature by Zhu, Y., Hu,J., & Yeung, K. (2009) (“Effect of soft segment crystallization and hardsegment physical crosslink on shape memory function in antibacterialsegmented polyurethane ionomers”, Acta Biomaterialia, 5(9), 3346), whichis incorporated herein by reference in its entirety. Due to the crimpingcaused by stretching, stretch-ability and thermal plasticity areprerequisites.

The following examples accompanied will illustrate the present inventionin more detail:

Estane® S385A is chosen in elastomer part. Hardness is 85A. Ultimateelongation is 780%. Polycaprolactone diol (Mn=10000) based SMP with MDI(4,4′-Methylenebis(phenylisocyanate)), BDO (1,4-Butanediol), orN,N-bis(2-hydroxyethyl)-isonicotinamide (BIN) in hard segments is usedin SMP part as reported in literature (Zhu, Y., Hu, J., & Yeung, K.(2009), “Effect of soft segment crystallization and hard segmentphysical crosslink on shape memory function in antibacterial segmentedpolyurethane ionomers”, Acta Biomaterialia, 5(9), 3346). T_(r) of SMPused is 48 degree Celsius or SMP part can be Diaplex MM4520 with Tg of45 degree Celsius.

TABLE 1 Physical properties of example 1 to example 7. Elastomer:SMPDiameter Coil Shape Weight (Filament) or Elongation Coil Number recoveryExample Shape Elastomer SMP Ratio thickness (tape) % Diameter Per cmtemperature 1 Filament Estane ®S385A *Polycaprolactone 7:3 1.2 mm 100 3mm 9 48° C. based SMP-1 2 Filament Estane ®S385A **SMP-2 8:2 1.2 mm 1005 mm 10 45° C. 3 Filament Estane ®S385A **SMP-2 8:2 1.2 mm 150 4 mm 1145° C. 4 Filament Estane ®S385A **SMP-2 8:2 1.2 mm 200 3 mm 12 45° C. 5Tape Estane ®S385A ***Polycaprolactone 6:4 0.7 mm 100 7 mm 7 43° C.based SMP-3 6 Tape Estane ®S385A ***Polycaprolactone 6:4 0.7 mm 200 5 mm9 43° C. based SMP-3 7 Tape Estane ®S385A ***Polycaprolactone 6:4 0.7 mm300 3 mm 13 43° C. based SMP-3 8 Tape Estane ®S385A ***Polycaprolactone7:3 0.9 mm 100 3 mm 13 80° C. based SMP-3 9 Filament Estane ®S385A^(#)SMP-4 55:45 0.100 mm 100 0.508 mm 32 40° C. 10 FilamentEstane ®S385A ^(##)Poly(hexylene 55:45 0.105 mm 100 0.509 mm 28 40° C.adipate) based SMP-5 Keys:- *Polycaprolactone based SMP-1 is from: Zhu,Y., Hu, J., & Yeung, K., “Effect of soft segment crystallization andhard segment physical crosslink on shape memory function inantibacterial segmented polyurethane ionomers”, Acta Biomaterialia,2009, 5(9), 3346; **SMP-2 is Diaplex ™ shape memory polymer 4520;***Polycaprolactone based SMP-3 is from: Zhu Y, Hu J, Choi K F, et al.Crystallization and melting behavior of the crystalline soft segment ina shape-memory polyurethane ionomer[J], Journal of Applied PolymerScience, 2008, 107(1): 599-609; ^(#)SMP-4 is a blend of two SMPs byusing Diaplex ™ shape memory polymer 4520 and 3520 with the weight ratioof 50/50; ^(##)SMP-5 is from: Chen S., Hu J., Liu Y., et al. Effect ofSSL and HSC on morphology and properties of PHA based SMPU synthesizedby bulk polymerization method[J]. Journal of Polymer Science Part B:Polymer Physics, 2007, 45, 444

Example 1

For bi-component filament with 1.2 mm diameter, elastomer Estane® S385Aand polycaprolactone based SMP are coextruded with weight ratio 7:3(melt flow pump control) by using side-by-side nozzle. Prior toprocessing, all pellets must be dried at 104 degree Celsius for 2-4hours. The barrel temperature of extruder would be 180˜195 (zone 1),185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius.Screw speed is 180˜200 rpm. The filament is cooling through cold waterwith a temperature of about 15 degree Celsius from nozzle without anystretching process. The bi-component filament prepared can show the“smart coil” function, in which stretching to 100% elongation ratio cangive rise to crimping shape with 3 mm of coil diameter, 9 turns per cmand heating up to about 48-80 degree Celsius leads to straight shapeback.

Example 2

For bi-component filament with 1.2 mm diameter, elastomer Estane® S385Aand Diaplex MM4520 SMP are coextruded with a weight ratio of 8:2 (meltflow pump control) by using eccentric nozzle. Prior to processing, allpellets must be dried at 104 degree Celsius for 2-4 hours. The barreltemperature of extruder would be 180˜195 (zone 1), 185˜200 (zone 2),190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is180˜200 rpm. The filament is cooling through cold water with atemperature of about 15 degree Celsius from nozzle without anystretching process. The bi-component filament prepared can show the“smart coil” function, in which stretching to 100% elongation ratio cangive rise to crimping shape with 5 mm of coil diameter, 10 turns per cmand heating up to about 45-50 degree Celsius leads to straight shapeback.

Example 3

For bi-component filament with 1.2 mm diameter, elastomer Estane® S385Aand Diaplex MM4520 SMP are coextruded with a weight ratio of 8:2 (meltflow pump control) by using eccentric nozzle. Prior to processing, allpellets must be dried at 104 degree Celsius for 2-4 hours. The barreltemperature of extruder would be 180˜195 (zone 1), 185˜200 (zone 2),190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is180˜200 rpm. The filament is cooling through cold water with atemperature of about 15 degree Celsius from nozzle without anystretching process. The bi-component filament prepared can show the“smart coil” function, in which stretching to 150% elongation ratio cangive rise to crimping shape with 4 mm of coil diameter, 11 turns per cmand heating up to about 45 degree Celsius leads to straight shape back.

Example 4

For bi-component filament with 1.2 mm diameter, elastomer Estane® S385Aand Diaplex MM4520 SMP are coextruded with a weight ratio of 8:2 (meltflow pump control) by using eccentric nozzle. Prior to processing, allpellets must be dried at 104 degree Celsius for 2-4 hours. The barreltemperature of extruder would be 180˜195 (zone 1), 185˜200 (zone 2),190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is180˜200 rpm. The filament is cooling through cold water with atemperature of about 15 degree Celsius from nozzle without anystretching process. The bi-component filament prepared can show the“smart coil” function, in which stretching to 200% elongation ratio cangive rise to crimping shape with 3 mm of coil diameter, 12 turns per cmand heating up to about 45-60 degree Celsius leads to straight shapeback.

The coil diameter and coil number per cm were measured for bi-componentfilament with 1.2 mm diameter, elastomer Estane® S385A and polyurethanebased SMP being coextruded with a weight ratio of 8:2 (melt flow pumpcontrol) by using eccentric nozzle (FIG. 4A). With the elongationpercentage from 100% to 200%, the coil diameter is decreasing from 5 mmto 3 mm, and the coil number per cm is increasing from 10 to 12.

Example 5

For bi-component tape with 0.7-mm thickness, elastomer Estane® S385A andpolycaprolactone based SMP are coextruded with weight ratio 6:4 (meltflow pump control) by using layer by layer slot die. Prior toprocessing, all pellets must be dried at 104 degree Celsius for 2-4hours. The barrel temperature of extruder would be 180˜195 (zone 1),185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius.Screw speed is 180˜200 rpm. The tape is cooling through cold water witha temperature of about 15 degree Celsius from nozzle without anystretching process. The bi-component tape prepared can show the “smartcoil” function, in which stretching to 100% elongation ratio can giverise to crimping shape with 7 mm of coil diameter, 7 turns per cm, andheating up to about 43 degree Celsius leads to straight shape back.

Example 6

For bi-component tape with 0.7-mm thickness, elastomer Estane® S385A andpolycaprolactone based SMP are coextruded with weight ratio 6:4 (meltflow pump control) by using layer by layer slot die. Prior toprocessing, all pellets must be dried at 104 degree Celsius for 2-4hours. The barrel temperature of extruder would be 180˜195 (zone 1),185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius.Screw speed is 180˜200 rpm. The tape is cooling through cold water witha temperature of about 15 degree Celsius from nozzle without anystretching process. The bi-component tape prepared can show the “smartcoil” function, in which stretching to 200% elongation ratio can giverise to crimping shape with 5 mm of coil diameter, 9 turns per cm, andheating up to about 43 degree Celsius leads to straight shape back.

Example 7

For bi-component tape with 0.7-mm thickness, elastomer Estane® S385A andpolycaprolactone based SMP are coextruded with weight ratio 6:4 (meltflow pump control) by using layer by layer slot die. Prior toprocessing, all pellets must be dried at 104 degree Celsius for 2-4hours. The barrel temperature of extruder would be 180˜195 (zone 1),185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius.Screw speed is 180˜200 rpm. The tape is cooling through cold water witha temperature of about 15 degree Celsius from nozzle without anystretching process. The bi-component tape prepared can show the “smartcoil” function, in which stretching to 300% elongation ratio can giverise to crimping shape with 3 mm of coil diameter, 13 turns per cm, andheating up to about 43 degree Celsius leads to straight shape back.

The coil diameter and coil number per cm were measured for bi-componenttape with 0.7 mm thickness, elastomer Estane® S385A and polycaprolactonebased SMP being coextruded with a weight ratio of 6:4 (melt flow pumpcontrol) by using layer by layer slot die (FIG. 4B). With the elongationpercentage from 100% to 200%, the coil diameter is decreasing from 7 mmto 3 mm, and the coil number per cm is increasing from 7 to 13.

Example 8

For bi-component tape with 0.9-mm thickness, elastomer Estane® S385A andpolycaprolactone based SMP are coextruded with weight ratio 7:3 (meltflow pump control) by using layer by layer slot die. Prior toprocessing, all pellets must be dried at 104 degree Celsius for 2-4hours. The barrel temperature of extruder would be 180˜195 (zone 1),185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius.Screw speed is 180˜200 rpm. The tape is cooling through cold water witha temperature of about 15 degree Celsius from nozzle without anystretching process. The bi-component tape prepared can show the “smartcoil” function, in which stretching to 100% elongation ratio can giverise to crimping shape with 3 mm of coil diameter, 13 turns per cm andheating up to about 40-80 degree Celsius leads to straight shape back.

Example 9

For bi-component filament with 0.1 mm diameter, elastomer Estane® S385Aand blended two SMPs of Diaplex™ shape memory polymer 4520 and 3520 withthe weight ratio of 50/50 are coextruded with weight ratio 55:45 (meltflow pump control) by using side-by-side nozzle. Prior to processing,all pellets must be dried at 104 degree Celsius for 2-4 hours. Thebarrel temperature of extruder would be 180˜195 (zone 1), 185˜200 (zone2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is180˜200 rpm. The filament is cooling through cold water with atemperature of about 15 degree Celsius from nozzle without anystretching process. The bi-component filament prepared can show the“smart coil” function, in which stretching to 100% elongation ratio cangive rise to crimping shape with 0.508 mm of coil diameter, 32 turns percm and heating up to about 40 degree Celsius leads to straight shapeback.

Example 10

For bi-component filament with 0.105 mm diameter, elastomer Estane®S385A and Poly(hexylene adipate) based SMP are coextruded with weightratio 55:45 (melt flow pump control) by using side-by-side nozzle. Priorto processing, all pellets must be dried at 104 degree Celsius for 2-4hours. The barrel temperature of extruder would be 180˜195 (zone 1),185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius.Screw speed is 180˜200 rpm. The filament is cooling through cold waterwith a temperature of about 15 degree Celsius from nozzle without anystretching process. The bi-component filament prepared can show the“smart coil” function, in which stretching to 100% elongation ratio cangive rise to crimping shape with 0.508 mm of coil diameter, 28 turns percm and heating up to about 40 degree Celsius leads to straight shapeback.

It should be apparent to those skilled in the art that manymodifications besides those already described are possible withoutdeparting from the inventive concepts herein. The inventive subjectmatter, therefore, is not to be restricted except in the spirit of thedisclosure. Moreover, in interpreting the disclosure, all terms shouldbe interpreted in the broadest possible manner consistent with thecontext. In particular, the terms “includes”, “including”, “comprises”and “comprising” should be interpreted as referring to elements,components, or steps in a non-exclusive manner, indicating that thereferenced elements, components, or steps may be present, or utilized,or combined with other elements, components, or steps that are notexpressly referenced.

1. A linear bi-component filament, fiber, or tape comprising: a firstelastomeric component having a cross-sectional area of at least greaterthan approximately 50 percent of the filament, fiber, or tape, andhaving a glass transition temperature of approximately −125 degrees to−10 degrees Celsius; a second shape-memory polymeric component having across-sectional area of at least lower than approximately 50 percent andbeing selected from one or more of a thermoplastic polyester-based orpolyether based shape memory polyurethane, wherein said polyester basedpolymer comprises a polycaprolactone-based polymer, wherein the secondshape-memory polymeric component is positioned within the bi-componentfilament, fiber, or tape, such that a region of the second shape-memorypolymeric component is asymmetrically disposed with respect to a centralcore of the bi-component filament, fiber, or tape, and wherein the shapememory polymer has a selectively engineered shape recovery temperatureT_(r) between approximately 25° C. and 90° C. wherein the firstelastomeric component is more elastic than that of the secondshape-memory polymeric component at or lower than the selectivelyengineered shape recovery temperature.
 2. A linear bi-componentfilament, fiber, or tape comprising: a first elastomeric componenthaving a cross-sectional area of at least lower than approximately 50percent of the filament, fiber, or tape, and having a glass transitiontemperature of approximately −125 degrees to −10 degrees Celsius; asecond shape-memory polymeric component having a cross-sectional area ofat least greater than approximately 50 percent and being selected fromone or more of a thermoplastic polyester-based or polyether based shapememory polyurethane, wherein said polyester based polymer comprises apolycaprolactone-based polymer, wherein the second shape-memorypolymeric component is positioned within the bi-component filament,fiber, or tape, such that a region of the second shape-memory polymericcomponent is asymmetrically disposed with respect to a central core ofthe bi-component filament, fiber, or tape, and wherein the shape memorypolymer has a selectively engineered shape recovery temperature T_(r)between approximately 25° C. and 90° C. wherein the first elastomericcomponent is more elastic than that of the second shape-memory polymericcomponent at or lower than the selectively engineered shape recoverytemperature.
 3. The linear bi-component filament, fiber, or tape ofclaim 1, wherein the filament, fiber, or tape is configured to assume asubstantially helical configuration upon elongation of approximately 50%to approximately 300%, with the coil number per centimeter increasingwith the increase of the elongation percentage or the time period ofelongation.
 4. The linear bi-component filament, fiber, or tape of claim2, wherein the filament, fiber, or tape is configured to assume asubstantially helical configuration upon elongation of approximately 50%to approximately 300%, with the coil number per centimeter increasingwith the increase of the elongation percentage or the time period ofelongation.
 5. The linear bi-component filament, fiber, or tape of claim1, wherein the filament, fiber, or tape is configured to assume asubstantially helical configuration upon elongation of approximately 50%to approximately 300%, wherein the coil diameter is from 0.5 to 7 mm. 6.The linear bi-component filament, fiber, or tape of claim 2, wherein thefilament, fiber, or tape is configured to assume a substantially helicalconfiguration upon elongation of approximately 50% to approximately300%, wherein the coil diameter is from 0.5 to 7 mm.
 7. The linearbi-component filament, fiber, or tape of claim 1, wherein the filament,fiber, or tape is configured to assume a substantially helicalconfiguration upon elongation of approximately 50% to approximately300%, wherein number of the turns per cm is from 7 to
 32. 8. The linearbi-component filament, fiber, or tape of claim 2, wherein the filament,fiber, or tape is configured to assume a substantially helicalconfiguration upon elongation of approximately 50% to approximately300%, wherein the number of turns per cm is from 7 to
 32. 9. The linearbi-component filament, fiber, or tape of claim 1, wherein thebi-component filament, fiber, or tape resumes a substantially linearshape upon heating to the selectively engineered shape recoverytemperature T_(r).
 10. The linear bi-component filament, fiber, or tapeof claim 2, wherein the bi-component filament, fiber, or tape resumes asubstantially linear shape upon heating to the selectively engineeredshape recovery temperature T_(r).
 11. The linear bi-component filament,fiber, or tape of claim 1, wherein the shape memory polymer ispolycaprolactone-based shape memory polymer with an average molecularnumber of
 10000. 12. The linear bi-component filament, fiber, or tape ofclaim 2, wherein the shape memory polymer is polycaprolactone-basedshape memory polymer with an average molecular number of
 10000. 13. Thelinear bi-component filament, fiber, or tape of claim 1, wherein thepolycaprolactone-based shape memory polymer is polycaprolactonediol-based shape memory polymer having hard segments selected from4,4′-Methylenebis(phenylisocyanate), 1,4-Butanediol orN,N-bis(2-hydroxyethyl)-isonicotinamide.
 14. The linear bi-componentfilament, fiber, or tape of claim 2, wherein the polycaprolactone-basedshape memory polymer is polycaprolactone diol-based shape memory polymerhaving hard segments selected from 4,4′-Methylenebis(phenylisocyanate),1,4-Butanediol or N,N-bis(2-hydroxyethyl)-isonicotinamide.
 15. Thelinear bi-component filament, fiber, or tape of claim 1, wherein thefirst elastomeric component is in a range of 10 to 90 wt. % of the totalweight of the bi-component filament, fiber, or tape while the secondshape-memory polymeric component is in a range of 90 to 10 wt. % of thetotal weight of the bi-component filament, fiber, or tape, wherein theweight ratio between the first elastomeric component and the secondshape-memory polymeric component is 1-9:9-1 so long as the positioningof the first elastomeric component and the second shape-memory polymericcomponent with respect to the cross-sections along the bi-componentfilament, fiber, or tape remains asymmetrical.
 16. The linearbi-component filament, fiber, or tape of claim 2, wherein the firstelastomeric component is in a range of 10 to 90 wt. % of the totalweight of the bi-component filament, fiber, or tape while the secondshape-memory polymeric component is in a range of 90 to 10 wt. % of thetotal weight of the bi-component filament, fiber, or tape, wherein theweight ratio between the first elastomeric component and the secondshape-memory polymeric component is 1-9:9-1 so long as the positioningof the first elastomeric component and the second shape-memory polymericcomponent with respect to the cross-sections along the bi-componentfilament, fiber, or tape remains asymmetrical.
 17. The linearbi-component filament, fiber, or tape of claim 1, wherein the firstelastomeric component comprises one or more of polyester andpolyether-based polyurethanes.
 18. The linear bi-component filament,fiber, or tape of claim 2, wherein the first elastomeric componentcomprises one or more of polyester and polyether-based polyurethanes.